Fluorine-containing polymer compositions are suitably used as pint resins. Paint resins are required to have good storage stability under the state of solution. In addition, it is desirable that the resin solution is colorless and clear.
The patent reference 1 relates to a method for producing a fluorine-containing copolymer and describes that smooth progress of the copolymerization reaction and storage stability of varnish containing the formed copolymer are achieved by subjecting a monomer mixture containing a fluoroolefin and an alkyl vinyl ether to copolymerization in a polymerization medium containing a lower alkylbenzene and a component having a boiling point lower than the lower alkylbenzene in the presence of an alkali metal carbonate. Potassium carbonate is mentioned as an example of the alkali metal carbonate.